Ammonia is a key component of fertilizers, a crucial industrial chemical and a carbon-free fuel. Electrosynthesis of ammonia from nitrogen under ambient conditions presents an attractive alternative to the centralized Haber–Bosch process. Although lithium- and calcium-mediated nitrogen reduction (Li-NRR and Ca-NRR) show promise, long-term continuous ammonia electrosynthesis at high rates will be needed for industrial application. In this Perspective we argue that for Li-NRR and Ca-NRR to operate sustainably, the use of continuous-flow reactors—in which NRR is coupled with the hydrogen oxidation reaction, avoiding non-sustainable proton sources and electrolyte oxidation—is essential. Providing the necessary protons via hydrogen oxidation is vital for the sustainable production of ammonia and long-term system stability. We propose strategies such as optimizing the solid–electrolyte interphase design, refining the electrode and reactor engineering to enhance the system stability and ammonia production rate. We also strongly advocate the exploration of electrocatalytic routes for surpassing the theoretical energy efficiency limit of Li/Ca-NRR.

氨是化肥、重要工业化学品和无碳燃料的关键成分。在环境条件下用氮电合成氨是集中式哈伯-博世工艺的一种有吸引力的替代方案。尽管锂和钙介导的氮还原（Li-NRR 和 Ca-NRR）显示出前景，但工业应用仍需要长期连续高速率氨电合成。在本视角中，我们认为，要使 Li-NRR 和 Ca-NRR 可持续运行，使用连续流反应器（其中 NRR 与氢氧化反应相结合，避免不可持续的质子源和电解质氧化）至关重要。通过氢氧化提供必要的质子对于氨的可持续生产和长期系统稳定性至关重要。我们提出了优化固体电解质界面设计、改进电极和反应器工程等策略，以提高系统稳定性和氨产率。我们还强烈主张探索电催化路线以超越Li/Ca-NRR的理论能效极限。